The present invention relates to a coordinate position detecting method and a display apparatus involving the use of the method.
In a display apparatus such as a touch-panel for use in a plasma display panel (hereinafter referred to as PDP) or for use in a Braun tube (hereinafter referred to as CRT), it is necessary for a finger-touched position to be detected on a coordinate system.
As one method for detecting a position touched by a finger on a touch-panel, there in known a system capable of calculating a finger-touched position on a coordinate system. FIG. 10 shows one example of a coordinate system capable of optically detecting a coordinate position touched by a finger.
Referring to FIG. 10, a plurality of light emitting elements Ax1-Axn and Ay1-Ayn are respectively arranged on one longitudinal edge and one lateral edge of a display surface 1. A plurality of light receiving elements Bx1-Bxn and By1-Byn are respectively arranged on the other longitudinal edge and the other lateral edge. Infrared light beams emitted from the light emitting elements are received by the light receiving elements.
The above-described touch panel is so formed that when any optional position P (hereinafter referred to as touch position) of display surface 1 is touched by a finger or a touch pen, lights emitted from corresponding light emitting elements will be blocked, so that they will not be received by corresponding light receiving elements. By detecting the coordinate position of touch point according to X axis and Y axis, it is possible to specify the touch position p in accordance with the positions of the light receiving elements (not receiving lights at this time).
In a conventional touch panel such as the above-described touch panel, each pair of a light emitting element and a light receiving element are required to be disposed with a predetermined interval formed between them. In this way, a predetermined resolution corresponding to the number of the arranged light emitting elements and light receiving elements may be obtained. If the resolution is to be improved, it will be necessary to increase the number of the light emitting elements and the light receiving elements. As a result, the total number of the parts forming the touch panel will have to be increased, thus undesirably increasing the production cost. Moreover, if the light emitting elements and the light receiving elements are increased, a corresponding space will also have to be enlarged. However, since there is a limit in a space in which a touch panel is disposed, it is not allowed to increase the number of the light emitting elements and the light receiving elements as many as desired. On the other hand, even if it is allowed to increase the number of the light emitting elements and the light receiving elements, a circuit board for mounting an electronic circuit for processing signals will also have to be large. Consequently, in view of the space limitation, it is not easy to increase the number of the light emitting elements and light receiving elements, thus renderring it difficult to obtain an increased resolution (resolving power).
Detection of a coordinate position in each direction will be described below. In the horizontal direction (X axis direction), scanning is successively performed from the light emitting element Ax1 to the light emitting element Axn, so that a coordinate position can be detected in accordance with a position where an infrared light beam is blocked. Similarly, in the vertical direction (Y axis direction), scanning is successively performed from the light emitting element Ay1 to the light emitting element Ayn, so that a coordinate position can be detected in accordance with a position where the infrared light beam is blocked. In other words, a scanning operation is performed in X axis direction using each light emitting element arranged in X axis direction, and a scanning operation is also performed in Y axis direction using each light emitting element arranged in Y axis direction.
However, the above-described conventional scanning method needs a considerable amount of time to complete the detection of coordinate position, thus undesirably rendering the display apparatus to have only a bad operability.
Namely, it is necessary to repeatedly perform the lightening scanning from initial light emitting elements (Ax1, Ay1) to final light emitting elements (Axn, Ayn). If the number of coordinate positions (to be detected) has increased, it is necessary to have an increased amount of time for the detection, rendering it difficult to avoid a bad operability of the touch panel.
It is an object of the present invention to provide an improved coordinate position detecting method and a display apparatus using the method, ensuring an improved resolution (resolving power) and a shortened time necessary for detecting coordinate positions, as well as an improved operability for the display apparatus, thereby solving the above-mentioned problem existing in coordinate position detection in the above-discussed prior art.
In a first aspect of the present invention, there is provided a coordinate position detecting method using a plurality of light emitting elements and a plurality of light receiving elements located on mutually opposite sides, all the elements being arranged at a predetermined interval in horizontal and vertical directions, with each pair of mutually opposed light emitting element and light receiving element forming a light beam path, such that the coordinate position of a light blocking object can be detected once the light beam path is blocked, said method comprising: storing N previous coordinate datas obtained when detecting a movement of the light blocking object, using n (1xe2x89xa6nxe2x89xa6N) coordinate datas of the N previous coordinate datas to calculate a coordinate position of the light blocking object; and changing the number of the coordinate datas for use in calculating the coordinate position, in accordance with a speed of the movement of the light blocking object.
In a second aspect of the present invention, when a moving speed of the light blocking object is high, the number of coordinate datas for use in forming the said coordinate position is reduced, when the moving speed of the light blocking object is low, the number of coordinate datas for use in forming the said coordinate position is increased.
In a third aspect of the present invention, only a predetermined number of the light emitting elements are successively caused to perform scanning operation, which light emitting elements are located before and after a coordinate position at which the light blocking object has been detected, thereby detecting the coordinate position of the light blocking object.
In a fourth aspect of the present invention, only a predetermined number of the light emitting elements are successively caused to perform scanning operation, which light emitting elements are located before and after a coordinate position at which the light blocking object has been detected, while the scanning action of other light emitting elements are reduced, thereby detecting the coordinate position of the light blocking object.
In a fifth aspect of the present invention, the number of the light emitting elements scanning in the moving direction of the light blocking object is made larger than the number of the light emitting elements scanning in a direction opposite to the moving direction of the light blocking object. When a moved amount of the light blocking object is larger than a predetermined value, the number of light emitting elements in scanning operation is increased.
In a sixth aspect of the present invention, the number of the light emitting elements scanning in the moving direction of the light blocking object is made larger than the number of the light emitting elements scanning in a direction opposite to the moving direction of the light blocking object. When a moved amount of the light blocking object is larger than a predetermined value, the number of light emitting elements in scanning operation is increased.
In a seventh aspect of the present invention, there is provided a coordinate position detecting method using a plurality of light emitting elements and a plurality of light receiving elements located on mutually opposite sides, all the elements being arranged at a predetermined interval in horizontal and vertical directions, with each pair of mutually opposed light emitting element and light receiving element forming a light beam path, such that the coordinate position of a light blocking object can be detected once the light beam path is blocked, said method comprising: storing N previous coordinate datas obtained when detecting a movement of the light blocking object, using n (1xe2x89xa6nxe2x89xa6N) coordinate datas of the N previous coordinate datas to calculate a coordinate position of the light blocking object; and changing the number of the coordinate datas for use in calculating the coordinate position, in accordance with a speed of the movment of the light blocking object. The method further comprises: setting a first mode for successively rendering light emitting elements (in a first range including all the light emitting elements) to emit light beams to perform scanning operation, and for calculating a coordinate position at which a light beam is blocked; and setting a second mode for successively rendering light emitting elements (in a second range which is smaller than the first range but including a light emitting element corresponding to a beam-blocked position) to emit light beams and for calculating a coordinate position at which a light beam is blocked. In particular, after a beam-blocked position is calculated in the first mode, another beam-blocked position is calculated in the second mode.
In an eighth aspect of the present invention, the number of the light emitting elements scanning in the moving direction of the light blocking object is made larger than the number of the light emitting elements scanning in a direction opposite to the moving direction of the light blocking object, when a moved amount of the light blocking object is larger than a predetermined value, the number of light emitting elements in scanning operation is increased.
In a ninth aspect of the present invention, there is provided a coordinate position detecting method using a plurality of light emitting elements and a plurality of light receiving elements located on mutually opposite sides, all the elements being arranged at a predetermined interval in horizontal and vertical directions, with each pair of mutually opposed light emitting element and light receiving element forming a light beam path, such that the coordinate position of a light blocking object can be detected once the light beam path is blocked, said method comprising: storing N previous coordinate datas obtained when detecting a movement of the light blocking object, using n (1xe2x89xa6nxe2x89xa6N) coordinate datas of the N previous coordinate datas to calculate a coordinate position of the light blocking object; and changing the number of the coordinate datas for use in calculating the coordinate position, in accordance with a speed of the movment of the light blocking object. The method further comprises: setting a first mode for successively rendering light emitting elements (in a first range including all the light emitting elements) to emit light beams to perform scanning operation, and for calculating a coordinate position at which a light beam is blocked; and setting a second mode for successively rendering light emitting elements (in a second range which is smaller than the first range but including a light emitting element corresponding to a beam-blocked position) to emit light beams, and for calculating a coordinate position at which a light beam is blocked, further for reducing and rendering light emitting elements (in the first range not including the second range) to emit light beams so as to detect the coordinate position of the light blocking object. Specifically, after a beam-blocked position is calculated in the first mode, another beam-blocked position is calculated in the second mode.
In a tenth aspect of the present invention, during the second mode, the number of the light emitting elements scanning in the moving direction of the light blocking object is made larger than the number of the light emitting elements scanning in a direction opposite to the moving direction of the light blocking object. When a moved amount of light blocking object is larger than a predetermined value, the number of light emitting elements is increased.
In an eleventh aspect of the present invention, there is provided a display apparatus involving the use of the method according to any one of claims 1, 7 and 9, said apparatus comprising: a plurality of light emitting elements arranged on one side of two mutually opposed lines, and capable of emitting infrared light beams; a plurality of light receiving elements arranged on the other side of the two mutually opposed lines, and capable of receiving infrared light beams; and a controller connected respectively with the light emitting elements and the light receiving elements.
According to the first and second aspects of the present invention, since the coordinate position can be calculated in accordance with the coordinate data containing immediately previous data in relation to a detected coordinate position, it is possible to simplify a process for newly calculating a coordinate position through a newly sampling process. Further, since the number of coordinate datas to be used can be changed in accordance with the moving speed of a light blocking object, it is possible to obtain a resolution (resolving power) in accordance with the moving speed, thereby making it possible to prevent an undesired extension of a sampling time necessary for calculating a coordinate position.
According to the third and fourth aspects of the present invention, only a predetermined number of the light emitting elements are successively detected which are located before and after a coordinate position at which the light blocking object has been detected, while the scanning action using other light emitting elements are reduced, thereby detecting the coordinate position of the light blocking object. Therefore, it is possible to shorten a necessary time for calculating a coordinate position without lowering the resolution (resolving power).
According to the fifth and sixth aspects of the present invention, the number of the light emitting elements scanning in the moving direction of the light blocking object is made larger than the number of the light emitting elements scanning in a direction opposite to the moving direction of the light blocking object. Therefore, it is possible for the light emitting elements to perform a dense scanning operation ahead of the moving light blocking object. In other words, since it is possible that on the side away from the moving direction of light blocking object, the light emitting elements in scanning operation can be reduced, it is possible to shorten a necessary time for calculating a coordinate position without lowering the resolution (resolving power).
According to the seventh and ninth aspects of the present invention, a first mode is set for successively rendering light emitting elements (including all the light emitting elements) to emit light beams, a second mode is set for successively rendering light emitting elements (fewer than all the light emitting elements but containing a light emitting element corresponding to a beam-blocked position) to emit light beams. When the beam-blocked position calculated in the first mode has changed, the changed position is calculated not by the first mode but by the second mode. At this time, it is not necessary to use the first mode to render all the light emitting elements to emit light beams to perform full stroke scanning operation, but is allowed to perform only a short stroke scanning which is capable of calculating a beam-blocked position, thereby making it possible to require only a shorter time for calculating a beam-blocked potion than in the first mode.
According to the eighth and tenth aspects of the present invention, since it is possible that in the second mode, the number of the light emitting elements in scanning operation can be changed in accordance with the moving speed of the light blocking object, it is possible to shorten a necessary time for calculating a beam-blocked position, without decreasing the resolution (resolving power).
According to the eleventh aspect of the present invention, a controller can be used to set scanning operations of the light emitting elements corresponding to a moving speed of the light blocking object, thereby making it possible to shorten a necessary time for calculating a beam-blocked position, without decreasing the resolution (resolving power).
The above objects and features of the present invention will become better understood from the following description with reference to the accompanying drawings.